Automatic brake relay



y 1931- P. D. TARDIFF 0 ,196

AUTOMATIC BRAKE RELAY Filed March .3, 1926 INVENTOR,

PHILLIFD.TARDIF F Patented May 12, 1931 UNITED STATES PHILIP D. TABDIFF,OF DETROIT, MICHIGAN AUTOMATIC BRAKE RELAY Application filed March 3,1926. Serial No. 91,966.

My invention relates to a new and useful improvement in an automaticbrake relay and has for its object the provision of an automaticallyoperated mechanism adapted for use with electrically operated elevatorswhereby said elevators may be rendered more safe for the occupantsthereof.

With electrically operated elevators as now manufactured provision ismade that when the control switches of the elevators are opened thebrakes will be automatically set so that when the gates are opened andthe passengers are entering or leaving the elevator the danger of theelevator starting is supposed to be prevented.

Experience has shown however that in such elevators accidents may happenandinjury inflicted upon the passengers through the starting of theelevator while the gates are opened. A common cause of this is an arcingover at the control switches of the elevator which would release thebrake controls and permit the elevator to move either upwardly ordownwardly. Another reason for this is defective insulation or brokeninsulation.

In the present invention I have provided an auxiliary safety devicewhereby, so long as a circuit is complete through the brake coil it isimpossible for the operator to open the gates to permit the passengerseither to leave or enter. To effect this I have provided an automaticrelay.

The advantages and objects of the invention will further appear as thedescription proceeds.

The invention consists in the combination and arrangement of partshereinafter deand only those features which are necessary for the properillustration of the present invention have been pointed out in thisspecification.

In Fig. 1 I have shown the positive wire 9 through which the currentpasses and the negative wire 32. The wire 9 is connected through thewire 10 to a potential switch 11 which may be mounted upon the board andcontrolled therefrom. The wire 10 is connected through the potentialswitch 11 to the elevator control switches 12 and 13 each of whichco-operates with an auxiliary control switch 12 and 13 positionedbetween which is a resistance 14. The resistance is connected by thewire 15 to the brake coil 16 and thence to the wire 32, the auxiliarypotential switch 17, which may also be postioned upon the switch boardbeing interposed in this connection. The wire 15 is connected throughthe resistance 18 and the fuse 19 to one end of the magnetic coil 20-theother end being connected by the wire 21 and through the switch 17 tothe feed wire 32. The core 22 of this electric magnet is provided with across-head for closing the circuit through the contacts 23 and 27thecontact 23 being connected through the resistance 26 and the fuse bymeans of the wire 24 to the positive feed wire 9. The contact 27 isconnected through the operating gate switch 28 which is positioned inthe elevator cage to the motor 29 which is used for opening and closingthe elevator gates. The wire 31 connects through the emergency switchwhich is positioned in the cage to the motor 29-the construction is suchthat the current when either of the switches 12 or 13 is closed passesthrough the brake coil 16 and energizes the electro magnet 20 so as tobreak the circuit between the contacts 27 and 23. The auxiliarypotential switch 17 of course being closed at this time.

When such an arrangement is effected a closing of the switch 28 will noteffect a closing through the motor 29 so that the gates of the elevatorcage cannot be opened by means of themotor 29. Upon opening of theswitches 12 nd 1.3 whi h contr the elevatol by a suitable wire to thearmature, the circuit between the contacts 27 and 23 will be closed andit'is only when the switches 13 and 12 are openedthat is only when nocurrent is passing through the coil 20 that negative teed wire 43. Thewire 33 is connected through the wire 34 and the potential switch 35 andthrough the elevator control switches 36 and 37, 36 and 37, theresistance 38 and the wire 39 to the brake coil 40 which is alsoconnected to the negative feed .wire by means of the wire 44 throughauxiliary switch 44. The wire 39 is connected by the wire 41 toa contact42. The wire 43 is connected by means of the wire45 to the automaticgate switch 46, this gate switch comprising an extra contact on theinside of the car gate and being normally closed when the gate is halfopen.

One of the contacts of the gate switch 46 is connected by the wire 47tothe contact 48- a knife blade switch 49 serving to engage the contacts42 and 48 so as tov control the circuit between the lines 47 and 58 andthe lines 41 and 51. This switch 49 may be termed an emergency brakeswitch or an emergency relay disabling switch and is to be opened onlyin case of inoperativeness 01". the relays, or failure to function forany reason.

The contact 52 is connected to the wire 51 and the resistance 50 whichconnects with a fuse. The wire 51is also connected through the wire andthe resistance 54 to the contact 55. The contact 57 is connected bymeans of the wire 56 to the wire 58 which connects with a fuse and aresistance 59 and also the means or the wire 69 to the negative feedwire 43a fuse 70 being interposed in this wire 69. The core 71 of therelay carries a cross head 72 adapted upon movement in one direction foropening a circuit between the contacts 7 3 and 74 which are suitablywired to the gate controls. A secondary cross-head 75 is mounted on thecore 71 and adapted-for closing a circuit between the contacts 76 and57. The contact 76 being connected by the wire 7 7 to the relay 78. Thisrelay being connected by the wire 7 9 through the resistance 80 and thefuse 81 and the wire 82 to the positive feed wire 33; The core 83 of therelay 7 8 carries a cross head 84 adapted upon movement in one directionfor closing the circuit between the contact 85 which is suitablygrounded and the contact 55.

The operation of the device is such that the safety desired is obtainedin an electrically operated elevator of this class. The switch 46 isnormally open, and as previously stated, it is closed when the gates aremoved to partly open position. When the switch 49 is closed and theswitch 46 isclosed by opening of the gates, it either of the directionswitches 36 and 37 is closed, the coil 60 will: be energized, pullingthe core 62 downwardly, and closing connection between thecontacts 52and 67. thus energizing the'coil 68. When the coil 68 is energized thecore 71 is pulled down and the cross head 75 will en-Ico gage thecontacts 76 and 57, thus energizing the coil 78, upon which the core 83is pulled downwardly so that the cross head 84 engages the contacts 85and 55; When the coil 68 is energized the movement of the-coreWillithrow out the breaker and kill the board while at the same'time,the coil 78 is energiz'ed. At the same time, the cross head 72 willdisengage from the contacts 73 and 74, thus" breaking the gate circuit.When the coil 7 8 is energized the cross head or contact arm 84 will, asmentioned, close the circuit between the contacts 55 and 85. This lastclosed circuit holds the breaker out until the gates of the car areclosed, andwhen the gates ms or" the car are closed, the switch isopened and all of the coils de-energized, and the various contactsreleased to neutral. Thus it is seen hat when the safety control switch,which 7 closed upon the opening of the gate, isim closed, a circuit tothe relay is established,

which throws out the potential switch when the operating line is closed,either by undue closing of either of the switches 36 or 37, or

by an arcing. I When the operating line is closed the automatic brake,of course, will not set, but it is desirable to have these brakes set atall times when the gates are open. Therefore, it is evident that withthis invention operating as described, there is provided means formaintaining the operating line open so long as the gates are open.

Having thus described invention what I claim as new and desire to secureby Letters Patent is i In an electrically operated elevatorshav ingelectrically controlled gates and brakes and an operating line forsupplying electric current to the operating mechanism: directionswitches for controlling the flow of current through said operatingline; a switch normally closed upon the opening of said gates; and.means operable upon the closing of said second mentioned switch Whileeither of said direction switches is closed for breakin r the circuit tosaid operating line.

In testimony whereof, I have signed the foregoing.

PHILIP D. TARDIFF.

